This invention relates to a shielded wire construction, and particularly to such a construction wherein a helically wound central conductor has a special shield configuration extending helically with and substantially enclosing the central conductor, and providing the properties of a Faraday shield therefor.
A classical Faraday shield takes the form of a planar array of spaced parallel conductors grounded at one end. Such a configuration is found to have desirable shielding properties.
In the field of switching power supplies, it is common to use a transformer with E-shaped cores so that a flat sheet of copper can be inserted between the primary and secondary windings. Such shielding between primary and secondary circuits is for the purpose of electric shock protection pursuant to Underwriters Laboratories Requirements for Electronic Data Processing Units and Systems, paragraph 9A of UL 478, fifth edition.